Piston and independently operated



March 1952 A. IVANOFF ETAL PISTON AND INDEPENDENTLY OPERATEDDISTRIBUTING VALVE FOR RECIPROCATING PISTON ENGINES Filed March 51, 19455 Sheets-Sheet 2 March 18, 1952- WANOFF r 2,590,014

PISTON AND INDEPENDENTLY OPERATED DISTRIBUTING VALVE FOR RECIPROCATINGPISTON ENGINES Filed March 31, 1945 3 Sheets-Sheet 3 grave/77521!Patented Mar. 18, 1952 PISTON AND INDEPENDENTLY OPERATED DISTRIBUTINGVALVE FOR RECIPROCAT- ING PISTON ENGINES Alexander Ivanoff and GilesPhilip Eliot Howard,

Luton, England Application March 31, 1945, Serial No. 585,912 In GreatBritain March 21, 1944 Section 1, Public Law 690, August 8, 1946 Patentexpires March 21, 1964 14 Claims. 1

This invention relates to prime movers comprising reciprocating pistonsoperated by fluid pressure. The invention is particularly applicable tothose arrangements in which a reciprocating piston operated by fluidpressure (say steam) is direct coupled to the plunger of a reciprocatingpump, so that the piston and plunger reciprocates as one piece.

The invention is, however, applicable to all prime movers comprisingreciprocating pistons operated by fluid pressure, Whether the pistonoperates through a crank shaft and fly wheel or not, and whether itdrives the plunger of a re ciprocating pump or some other driven device.

The object of the invention is the provision of improved means forcontrolling the movement of the piston throughout the cycle so as togive it a desired characteristic. The invention, in its broadest aspect,consists in the arrangement that the valve means which control the flowof the pressure fluid to the cylinder are controlled jointly inaccordance with the movements both of the piston and of anotherindependently driven cyclically operating device.

In order that the invention may be the more clearly understood certainembodiments thereof ,will now be described, reference being made to theaccompanying drawings, wherein:

Figure 1 is a sectional side elevation of an arrangement in accordancewith the invention in which a reciprocating piston driven by steam isdirect coupled to the plunger of a reciprocating pump, the parts being.at the position of rest at the right hand end of the stroke.

Figure 2 is a section on line II-II of Figure 1.

Figure 2A is a sectional view generally corresponding to Figure 2, butshowing a modified arrangement thereof in the form of a duplex set.

Figure 3 is an outside view of the left hand portion of the arrangementof Figure 1, the position being that at which the stroke to the left hasbeen started.

Figure 4 is a similar view of the same, the parts being at the positionof rest at the left hand end of the stroke.

Figure 5 is a similar view of the same, the position being that at whichthe stroke to the right has been started.

Figure 6 is a side elevation of a similar arrangement, but having asomewhat different form of control gear, the position being that atwhich the stroke to the right is about half completed.

Figure 7 is a section on line VII-VII of Figure 6. I

Referring first to all the figures the same illustrate a steam cylinderI and a pump cylinder 2 arranged coaxially, the piston 3 of the steamcylinder I being rigidly coupled, by means of a piston rod 4, to thepump bucket or plunger 5 so that said piston and plunger reciprocate asone piece. The pump is of the common type In which, when the plunger 5moves from left to right, liquid is sucked through the inlet 6, into aspace I, and from there past a valve 8 (which lifts) into a space 9 andthence to the left hand end of the cylinder. Simultaneously liquid isforced from the right hand end of the cylinder into a space I0 andthence past a valve I I (which lifts) into a space I2 and. out at theoutlet, I3. In like manner, when the plunger 5 moves from right to leftliquid is sucked through inlet 6 into space I and past a valve I4 (whichlifts) into the space I0 and thence to the right hand end of thecylinder. Simultaneously liquid is forced from the left hand end of thecylinder into the space 9 and past a valve I5 into the space I2 and outat the outlet I3.

Steam for the steam cylinder I is supplied by way of a supply pipe I6and flows freely to the two ends of a valve chamber I! in whichreciprocates a piston valve I8. The valve chamber I'I communicates byway of conduits I9 and 20 and the two ends of the cylinder I and saidchamber I! also communicates at its centre, by way of a conduit 2I, withan exhaust pipe 22. As will be readily seen from the drawing the pistonvalve I8 has two valve pistons 23 and 24 which, in the mid position ofsaid valve, close said conduits I9 and 29. When said valve I8 moves tothe right from said mid position, the valve piston 23 uncovers theconduit I9 to admit live steam to the left hand end of the cylinder Iand the valve piston '24 uncovers the conduit 20 to connect the righthand end of the cylinder I to exhaust. The piston 3 accordingly movesfrom left to right. Conversely when said valve I8 moves to the left frommid position, the valve piston 24 uncovers the conduit 20 to admit livesteam to the right hand end of the cylinder, and the'valve piston .23uncovers to conduit I9 to connect the left hand end of the cylinder' toexhaust. The piston 3 accordingly moves from right to left.

In all the figures, control is effected through the medium of a cam 25which is continuously rotated by means of an independent prime mover 26.The valve I8 is coupled to said cam 25 in such a way that rotation ofsaid cam tends to reciprocate said valve continuously first in onedirection. and then in the other, and, at the same a substantiallyconstant length of stroke and hence displacement, whether liquid, gas orvapour is being pumped, and to give the piston a reduced velocity and/oracceleration at the ends of its stroke so as to enable the pump valvesto operate silently even under high speeds of operation of the primemover.

It may be pointed out that, owing to the angularity of the linkmechanism the cam will need to be somewhat asymmetrical to producesymmetrical movement of the piston.

It will be clear that there are many possible mechanical arrangementscapable of correlating the cam, piston valve and piston in the requiredway. Figures 6 and 7 illustrate one alternative mechanism for thispurpose. In'this mechanism the piston rod 4 has a cross head 21 carryinga rocking pin 28 as before, and, as before, a cross head lever 29 passesslidably through a diametrical hole in the head of the rocking pin. Thecross head lever 29 however, unlike the preceding arrangement, ispivoted about a fixed axis 43 near to its end remote from the crosshead, and, at its end remote from the cross head, carries the bearing 44for the cam shaft. As before, the cam is continuously rotated, and, inthe present case, the tendency of the piston 3 to return the pistonvalve 18 to the centre position is by virtue of the bodily movement ofthe cam, in response to the movement of said piston causing the crosshead lever 29 to rock about the pivot axis 43.

Thus, referring to Figure 6, assuming the cam 25 to be rotating in aclockwise direction, said cam, by virtue of its rotation, will betending to permit movement of the piston valve l8 to the right, and thusthe conduits l9 and will be uncovered in such a direction as to causethe piston 3 to be moving to the right. The cross head 21 willaccordingly be moving to the right ciprocates in a manner determined bythe shape of the cam.

In order for the motor 25 to rotate the cam, while the latter is makingits bodily to and fro movement as described, the cam shaft has a gearwheel 45 mounted on it, which is in train,

through the medium of a gear wheel 46 whose bearing is also carried bythe lever 29 as shown, with a gear wheel 41 which is coaxial with theaforesaid axis 43. A worm wheel 4! is mounted on the shaft of said gearwheel 41, said worm wheel being driven by .a worm coupled to the motor26. It will thus be seen that, without interruption of the continuity ofthe transmission from the motor 26 to the cam 25, through the elements40, 4|, 41, 4B, 45, the cam together with the gear wheels 45 and 46 arecapable of being rocked about the axis 43, the gear wheel 46 simplymoving to and fro around an arc of the gear wheel 41. This movement willhowever obviously produce a cyclical variation in the speed of rotationof the cam which must be taken account of in designing the cam contour.It may be mentioned that the gear wheel 46 is interposed between thegear wheels 45 and 41 merely for con- ;venience, of design. The gearwheel 45 mightbracket 38 on a base 39 as before.

equally well mesh direct with the gear wheel 41. The mechanismillustrated in Figures 6' and 7 enables the cam and gears to be totallyenclosed in a dust and oil tight casing 48. Thus thetwo parts of thelever 29 on opposite sides of the axis 43 are off set from each otherbeing joined by a shaft 49 coaxial with said axis 43; The oil tightbearing 50 for this shaft is sealed in a Wall of said casing 48, andthus the upper portion of the lever 29 is insidethe casing whereas thelower portion is outside the casing. Thus the cam and gears are allinside the casing as stated. The shaft of the piston valve l8 passesthrough an oil tight bush in the wall of the casing 48 as shown,

and the drive from the motor to the worm 40 also pass in sealed relationthrough a wall of said casing.

As will be seen the motor 26 is mounted on a As shown said base 39supports the bearing 50 and the bearing of the gear wheel 41 and wormwheel 4|, and also supports the casing 48.

It will be appreciated that the invention is applicable to otherarrangements than enginepump combinations such as described. For examplethe piston could operate through a crank, crank shaft and fly wheel, andin such case, the arrangement of control as described above results inthe automatic adjustment of the cut-off to the load, and in the speedbeing held exactly at the desired value regardless of variations insteam pressure or load, and this may be an advantage for certainapplications.

What we claim and desire to secure by Letters Patent is:

1. A prime mover comprising a cylinder, a piston reciprocatable in saidcylinder, valve means controlling the admission and exhaust of pressurefluid toand from said cylinder for reciprocating said piston, acyclically operating cam device, means independent of said prime moverfor driving said cam device and means operable on said valve means formoving said valve means in response jointly to the operation of said camdevice and to the movements of said piston so that said piston isreciprocated in a controlled manner with a characteristic depending onthe characteristic of said cam device.

2. A prime mover comprising a cylinder, a piston reciprocatable in saidcylinder, valve means displaceable to opposite sides of a neutralposition for controlling the admission and exhaust of pressure fluid toand from said cylinder for reciprocating said piston in oppositedirections, a cyclically operating cam device, means independent of saidprime mover for driving said cam device, and means responsive to saidcam device for reciprocating said valve means, and also responsive tomovement of said piston upon displacement of said valve means on eitherside of the neutral position, to restore said valve means to the neutralposition, so that said piston is reciprocated in a controlled mannerwith a characteristic depending on the characteristic of said camdevice.

3. A prime mover comprising a cylinder, a piston reciprocatable in saidcylinder, valve means controlling the admission and exhaust of pressurefluid to and from said cylinder for reciprocating said piston,displacement of saidvalve means on opposite sides of a neutral positionbeing adapted respectively to effect movement of said piston in oppositedirections, a cyclically operating cam device, means independent of saidprime mover for. driving said cam device, afloating lever, means wherebysaid floating lever is actuated by said cam device, means whereby saidfloating lever is actuated .by the reciprocating piston, and meanswhereby said valve means are actuated by said floating lever, wherebyoperation of said cam device tends to reciprocate said valve means, andwhereby movement of said piston in response to displacement of saidvalve means on either side of the neutral position tends to restore saidvalve means to the neutral position, so that said piston is reciprocatedin a controlled manner with a characteristic depending .on thecharacteristic of said cam device.

4. A prime mover comprising :a cylinder, a piston reciprocatable in saidcylinder, valve means controlling the admission and exhaust of pressurefluid to and from said cylinder for reciprocating said piston,displacement of said valve means on opposite sides of a neutral positionbeing .adaptedrespectively to effect movement of said piston in oppositedirections, a rotatable cam, means independent of said prime mover forrotating said cam, a floating lever, a roller carried by said lever andbearing against the cam surface of said cam, a piston rod for saidpiston, a cross head mounted on said piston rod, a rocking pin carriedby said cross head, said floating lever passing slidably through a holein .said rocking pin, and means coupling said floatton reciprocatable.in said cylinder, valve means controlling the admission and exhaust ofpressure fluid to and from said cylinder for reciprocating said piston,displacement of said valve means on opposite sides of a neutral positionbeing adapted respectively to effect movement of said piston in oppositedirections, a rotatable cam, means independent of said prime mover forrotating said cam, a floating lever, a roller carried by said lever andbearing against the cam surface of said cam, a piston rod for saidpiston, a cross head mounted on said piston rod, :a rocking pin carriedby said cross head, said floating lever passing slidably through a holein said rocking pin, and a rocking lever coupling said floating lever tosaid valve means, whereby rotation of said cam tends to reciprocate saidvalve means, and whereby movement of said piston in response todisplacement of said valve means on either side of a neutral positiontends to restore said Valve means to the neutral position so that saidpiston is reciprocated in a controlled manner with a characteristicdepending on the characteristic of said cam.

6. A prime mover comprising a cylinder, apiston reciprocatable in saidcylinder, valve means controlling the admission and exhaust of pressurefluid to and from said cylinder for reciprocating said piston,displacement of said valve means on opposite sides of a neutral positionbeing adapted respectively to effect movement of said piston in oppositedirections, a cyclically operating cam device, means independent of:saidprime mover for driving said cam device with a predetermined valvedisplacing and timing characteristic, means responsive to cyclicalnoperation of said cam device for reciprocating :said valve means, andmeans operable iupnn movement of said piston in response to displacementof said valve means on either side of the :neutral position foreffecting bodily movement of said cam device in the direction to restoresaid valve means to the neutral position, the cyclical operation of thecam device and the bodily dis placement of the cam device as aforesaidcausing controlled reciprocation of said piston with a characteristicdetermined by the characteristic of said cam device.

7. A prime mover comprising a cylinder, a piston reciprocatable in saidcylinder, valve means controlling the admission and exhaust of pressurefluid to and from said cylinder for .reciprocating said piston,displacement of said valve said piston in opposite directions, acyclically operating cam device, means independent of said prime moverfor driving said cam device with a predetermined valve displacing andtiming characteristic, means responsive to cyclical operation of saidcam device for reciprocating said valve means, a lever carrying said camdevice, said lever having a fixed pivotal axis, means coupling saidlever to said piston and operable upon movement of said piston inresponse to displacement of said valve means on either side of theneutral position for rocking said lever and for effecting bodilymovement of said cam device in the direction to restore said valve meansto the neutral position, the cyclical operation of the cam device andthe bodily displacement of the cam device as aforesaid causingcontrolled reciprocation of said piston with a characteristic determinedby the characteristic of said oam device.

8; A prime mover comprising a cylinder, a 'p'iston reciprocatable insaid cylinder, valve means controlling the admission and exhaust ofpressure fluid to and from said cylinder for reciprocating said piston,displacement of said valve means on opposite sides of a neutral positionbeing adapted respectively to effect movement-"of said piston inopposite directions, a cyclically operating cam device, meansindependent of said prime mover for driving .said cam devicedisplacement of said valve means on either :side

of the neutral position for rocking said :lever and for effecting bodilymovement of said :cam device in the direction to restore :said "valvemeans to the neutral position, the cyclical 'operation of the cam deviceand the bodily displacement of the cam device as aforesaid causingcontrolled reciprocation of said piston with a characteristicdeterminedby the characteristic of said cam device, said driving meansfor the cam device including a transmission train comprising a gearwheel concentric with the axis of said lever, and gear means carried bysaid lever and coupling said gear wheel to said cam device.

9. A prime mover comprising a cylinder, a piston reciprocatable in saidcylinder, valve means controlling the admission and exhaust ofpressurefluid :to and from said cylinder for reciproeating said piston,displacement of said valve means on opposite sides of a neutral positionbeing adapted respectively to effect movement of said piston in oppositedirections, a cyclically operating cam device, means independent of saidprime mover for driving said cam device with a predetermined valvedisplacing and timing characteristic, means responsive to cyclicaloperation of said cam device for reciprocating said valve means, a levercarrying said cam device, said lever having a fixed pivotal axis, meanscoupling said lever to said piston and operable upon movement of saidpiston in response to displacement of said valve means on either side ofthe neutral position for rocking said lever and for effecting bodilymovement of said cam device in the direction to restore said valve meansto the neutral position, the cyclical operation of the cam device andthe bodily displacement of the cam device as aforesaid causingcontrolled reciprocation of said piston with a characteristic determinedby the characteristic of said cam device, said driving means for the camdevice including a transmission train comprising a gear wheel concentricwith the axis of said lever, and gear means carried by said lever andcoupling said gear wheel to said cam device, said lever comprising ashaft coaxial with said fixed pivotal axis and two lever portions oneach side of said axis spaced from each other along said shaft, a casingfor said cam device, said gear wheel and said gear means, and a bearingfor said shaft in a wall of said casing, whereby one of said shaftportions is outside said casing, the means coupling said lever to saidpiston being connected to one of the two lever portions aforesaid.

10. In combination, a plurality of prime mov ers, each of said primemovers comprising a cylinder, a piston reciprocatable in said cylinder,movable valve means controlling the admission and exhaust of pressurefluid to and from said cylinder for reciprocating said piston, acyclically operating cam device, means independent of said prime moverfor driving said cam device with a predetermined valve displacing andtiming characteristic, means for moving said valve means in responsejointly to the operation of said cam device and to the movements of saidpiston and with controlling effect upon the reciprocation of said pistonaccording to the characteristics of said cam device, and means couplingthe cam devices of said prime movers so that they operate in unison.

11. A combination as claimed in claim 10, wherein the sum of the speedsof the pistons of said prime movers responsive to the controlling effectof the cam devices is always substantially the same.

12. In combination, a plurality of prime movers, each of said primemovers comprising a cylinder, a piston reciprocatable in said cylinder,movable valve means controlling the admission and exhaust of pressurefluid to and from said cylinder for reciprocating said piston, acyclically operating control device, means independent of said primemover for cyclically driving said control device with a predeterminedvalve displacing and timing characteristic, means for moving said valvemeans in response jointly to the cyclical operation of said controldevice and to the movement of said piston and with controlling effectupon the reciprocation of said piston according to the characteristic ofsaid control device, and means coupling the control devices of saidprime movers so that they operate in unison, the sum of the speeds ofthe pistons of said prime movers responsive to the controlling effect ofthe control devices being always substantially the same.

13. A combination as claimed in claim 10, wherein there are two primemovers and the two pistons move ninety degrees out of phase with eachother and the instantaneous speed of each when plotted against timeconforms substantially to a sine squared law in response to thecontrolling effect of the cam devices.

14. A combination as claimed in claim 12, wherein there are two primemovers and the two pistons move ninety degrees out of phase with eachother and the instantaneous speed of each when plotted against timeconforms substantially to a sine squared law in response to thecontrolling effect of the control devices.

ALEXANDER IVANOFF. GILES PHILIP ELIOT HOWARD.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 448,356 Miller Mar. 17, 18911,754,743 Diserens Apr. 15, 1930 1,772,121 Volz Aug 5, 1930 2,124,788Leman July 26, 1938 FOREIGN PATENTS Number Country Date 2,086 GreatBritain of 1885 B- KENNEDY March I, 1952 GLOVE Filed Aug. 24, 1949 IN VEN TOR. Ber! Ken rzc zlg BY W, adyegww ATTOR N EYS'

